A, B, C, D

B, A, D, C

C, D, A, B

D, A, B, C

primary succession

ecological succession

secondary succession

intermediate

primary

secondary

primary

secondary

Bushes and Shrubs

Oak trees

Mosses and Lichens 

A rose Bush

Lichens → Shrubs → Grasses → Trees

Lichens → tree → shrubs→Grasses

Grasses → Lichens → Shrubs → Trees

Lichens → Grasses → Shrubs → Trees

resource

invasive (non- native) species

primary succession

competition

A, B, C, D

D, C, B, A

B, A, D, C

C, D, A, B

primary succession 

secondary succession

both types of succession

lichens

grasses

small plants